Investigations into the nature of desiccation-sensitive, or recalcitrant, seed behavior have as yet failed to identify exact causes of this phenomenon. Experiments with Quercus nigra L. and Quercus alba L. were conducted to examine physiological and biochemical changes brought about by seed desiccation and to determine if there...

Buttonbush is a deciduous, wetland shrub or small tree that can reach 6 m in height but generally averages 1 to 3 m tall. The trunk base is often swollen. Branches are generally green when young but darken upon maturity and have conspicuous, raised lenticels. The short-petioled glossy green leaves are elliptic or lanceolate-oblong; they are mostly opposite but, on the...

We examined changes that occurred in acorns during storage at different temperatures and moisture contents over a period of 3 y. In general, we found that to achieve optimum viability, acorns must be stored fully hydrated. Acorns also survived longer and sprouted less while in storage if stored at ?2 °C (28 °F) instead of the usual 4 °C (39 °F). However, we suspect...

This map and accompanying descriptions were developed through participation with numerous individuals from federal and state agencies and non-governmental organizations using criteria defined in the National Hierarchical Framework of Ecological Units. Delineation generally involved the ?top-down approach? of subdividing section level units. A ?bottom-up approach? was...

Investigations of recalcitrant, or desiccation-sensitive, seeds have as yet failed to identify the causes of this phenomenon. Experiments with Guarea guidonia (L.) Sleumer (American muskwood) were initiated to determine the effects of desiccation on the physiology and biochemistry of the seeds of this tropical tree species. Seeds were air-dried at...

Beginning work on seeds of endangered and exotic species often means starting with little or no knowledge and working toward successful handling and storage. It is often found that, in the past, exotic or poisonous plants (such as poison ivy) have been regarded as high in nuisance value and low in usefulness. Thus little research has been done on the care and handling...

Roystonea regia is a rapidly growing tree that can reach 15-34.5 m in height and 61 cm in diameter. The stout, smooth trunk is not always straight, and many short air roots are attached at the base. It is primarily valued as an ornamental. The seeds contain oil which is sold commercially or used for livestock feed. The leaves are used for thatching...

After nearly 100 years of fire exclusion, introduced pests, and selective harvesting, a change in forest composition has occurred in many Inland West forests of North America. This change in forest structure has frequently been accompanied by increases in root diseases and/or an unprecedented buildup of fuels. Consequently, many forest managers are implementing plans...

The Madrean Archipelago or Sky Islands region of the southwestern United States and northern Mexico is recognized for its unique biological diversity, natural beauty, and cultural heritage. This 2012 conference brought together scientists, managers, students, and other interested parties from the United States and Mexico to share their knowledge and passion about the...

There are three noteworthy species of Parkinsonia grown in the United States. Palo verde is a thorny, green-barked shrub/small tree which can reach a height of 11 m. The name refers to the very noticeable green color of the smooth trunk of this drought-resistant tree of the hot southern deserts. The open-crowned trees have alternate, bipinnate...

Practical application of black carbon (biochar) to improve forest soil may be limited because biochar is hydrophobic. In a laboratory, we tested the water repellency of biochar application (mixed or surface applied) to two forest soils of varying texture (a granitic coarse-textured Inceptisol and an ash cap fine-textured Andisol) at four different application rates (0...

New cost-effective strategies are needed to reclaim soils disturbed from mining activity on National Forests. In addition, disposal of waste wood from local timber harvest operations or biosolids from waste water treatment plants can be expensive. Therefore, using organic byproducts for soil reclamation activities on National Forests may provide an opportunity to...

Restoration of structure and function of mixed-oak (Quercus spp.) forests is a focal issue of forest land managers in the eastern United States due to widespread regeneration failure and poor overstory recruitment of oaks, particularly on productive sites. Prescribed fire is increasingly used as a tool in oak ecosystem restoration, with the goal of reducing competition...